Wow, great pic and so much activity. When I was there on Thursday the birds were lying low in the cold wind. I never saw a hint of yellow. I never thought I'd do better on a snowy day so stayed home on Friday! Later this week I will head over there again, I WANT to see the horned larks and the longspur.
I did get a great look at a sharpie on Fourth Line just south of Britannia. I got out the car to check the area and the sharpie flew down in front of me and perched on the fence. Yes, a nice squared off tail. Nearest I've ever been to a hawk - now if only I'd had a camera with me!